Background & Facts

See also the skinny, pro & con, links

The Science

How warming works

The earth would be a chilly place if it weren't for a phenomenon known as the greenhouse effect. Energy from the sun hits earth and radiates back into the atmosphere; it would normally escape to space if some didn't get trapped by gases in the atmosphere, like heat gets trapped by glass in a greenhouse. These gases, called “green house gases,” include gases that are both naturally found in the atmosphere and man made - such as carbon dioxide, methane, nitrous oxide - as well as purely industrially produced gases. Carbon dioxide, which is released by burning fossil fuels (gas, coal, etc.), is considered the largest contributor to the green house effect.

Where the green house gases are coming from

We plucked this straight from the Energy Information Administration:

Note: CO2 emissions also come from non-energy related sources, including agriculture and waste production. See this Pew chart using 1990 stats.

How much we're heating up

Most scientists – and the US Environmental Protection Agency (EPA) - agree the planet is getting warmer; about 1° F over the past century. (There are exceptions.) Estimates of future temperature rises range from 2.2° – 10° F by the year 2100. (Note: new IPCC numbers came out in April, 2007. Joe hasn't taken the time to sift through the new numbers, but you can check out the report here.)

How much are we adding to the heat?

At least part of this warming is unavoidable - part of a cycle that occurs naturally over long periods of time. Most scientists, however, think human activities, particularly the burning of fossil fuels, also add to global warming, although there are a small number in the scientific community who do not believe there is a definite link between human activity and climate change.

The full story? Not everyone agrees that it's the greenhouse gases alone that are warming up the atmosphere (even though that's the consensus of the vast majority of climatologists). In one alternative theory, a 2005 Duke University study suggests the sun is shooting off more heat lately and could be responsible for 10 - 30% of recent warming.

For more on how much humans contribute to warming, the possible effects of warming and economic costs of curbing emissions, see Pro/Con.

The policies

Kyoto

The 1997 Kyoto Protocol is an international treaty that calls on governments to bring emissions down to 5.2% below 1990 levels by 2012. Over a hundred nations have signed on, but neither Clinton or Bush ever brought the treaty to the Senate for approval. Bush is unlikely to change his mind as he says the economic impacts would be too great and that more research is needed. Kyoto officially went into effect February 2005. (WP) World leaders are now beginning to think about what'll come after Kyoto when it expires in 2012 (WP) - with the US agreeing to participate in separate non-binding talks. (WP)

McCain-Lieberman I and II

Senators Lieberman and McCain have been pushing a "Climate Stewardship" act for years. Their 2003 version set a national cap on greenhouse gas emissions at 2000 levels by 2010, with options for companies to buy and sell emission credits. An earlier version of the bill also had a second phase that would have required even stronger restrictions by 2016. So far, all versions have been killed by Congress. In 2007, McCain-Lieberman would now cap emission at 2004 levels by 2012 - with a second, long-term phase slowly bringing down emissions by over a third by 2050. The House's companion bill is known as the Gilchrest-Olver Climate Stewardship Act. (Pew)

Congressional action in 2007

With McCain on the campaign trail, a number of other senators, including Lieberman, are taking the lead on global warming proposals. Once bill would cap greenhouse gas emissions at 2006 levels by 2020, giving industry the ability to trade emissions points (NYT); a more stringent plan from Carper would cap emissions at 2001 levels by 2015. The front runner bill, offered by Lieberman and John Warner, would get emissions down by 57% (from 1990 levels) by 2050 using a cap & trade program. The New York Times compared some plans in this graphic.

The House, which is pushing for a climate change vote for the fall, is also wrestling with a pile of differing opinions, many spelled out in this Washington Post article. A proposal from the Energy Chair would tack on a 50cents/gallon gas tax as well as a $50/ton tax on carbon emissions to bring down emissions.

See also WaPo's October 2007 recap of carbon bills in the works.

Bush's economic incentives and tech initiatives

The president doesn't deny that global warming may be a problem; his tactics for addressing climate change, however, are more cautious. His policies prefer to provide incentives to private industry to voluntarily reduce emissions. Critics, however, say these incentives aren't effective enough. (A 2006 GAO report suggests that voluntary efforts have lukewarm results.)

Bush also supports putting money into developing alternative energies as well as building new nuclear reactors, both of which do not emit carbon dioxide. (WP) At the same time, he supports higher gas mileage standards and mandating that more fuel come from renewable sources like ethanol.

Stateside, cityside - and courtside

Impatient with the progress of climate control legislation in DC, many states have taken their own initiatives to cut back emissions at home, with nine Northeastern states - and possibly the West Coast - working on a cross-state plans to lower emissions (NYT & WP & WP). 522 cities, meanwhile, are also leap-frogging the feds to "sign on" to Kyoto, vowing to meet the foreign treaty's emission standards within their municipal boundaries (WP).

Eight states - California, Connecticut, Iowa, New Jersey, New York, Rhode Island, Vermont and Wisconsin – and NYC have also joined forces to sue five of the countries largest power plants, in an attempt to force industry to curb CO2 emissions.

In a separate suit, twelve states went to court to force the Environmental Protection Agency (EPA) to regulate CO2, saying the EPA has the authority and responsibility to do so under the Clean Air Act - which the EPA denied (WP). The Supreme Court ruled in April 2007 that the EPA does, indeed, have the authority to regulate CO2 and that it can't dismiss its duty to do so out of hand - but it leaves it up to the EPA if and how it will regulate CO2 (WP). That could be a slow process (WP).

Meanwhile many of the same states have taken a second shot at the EPA with a similar - but more narrowly defined - suit (AP), while they also are waiting on a waiver from the EPA so that they can set tighter emission standards of their own (NYT).

Updated November 11, 2007

Did we miss something, let some slant slip in, lose a link - or do you just have something to say? Drop a line below! In the spirit of open dialogue, cJ asks you keep it civil, keep it real and keep it focused on the message, not the messenger. See our policy page for more on what that all means.